Dunoon to Loch Long 132 Kv OHL Rebuild Consultation Document
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Dunoon to Loch Long 132 kV OHL Rebuild Consultation Document October 2020 REF: 70065799-LT193_CD CONTENTS GLOSSARY 1 PREFACE 3 EXECUTIVE SUMMARY 4 1. INTRODUCTION 5 1.1 Purpose of the Document 5 1.2 Document Structure 5 1.3 Next Steps 5 2. THE PROPOSALS 6 2.1 The Need for the Project 6 2.2 Preferred Technology Solution 6 2.3 Alternative Options Considered 6 2.4 Proposals Overview 7 3. ROUTE SELECTION PROCESS 9 3.1 Guidance Document 9 3.2 Area of Search 9 3.3 Baseline Conditions 9 3.4 Route Identification and Selection Methods 10 3.5 Appraisal Method 11 4. DESCRIPTION OF THE ROUTE OPTIONS 14 4.1 Identification of Sections and Route Options 14 5. BASELINE CONDITIONS 17 5.1 Introduction 17 5.2 Environmental Constraints 17 5.3 Engineering Constraints 22 5.4 Economic Constraints 23 6. COMPARATIVE APPRAISAL 24 6.1 Environmental Appraisal 24 6.2 Engineering Appraisal 32 6.3 Economic Appraisal 35 6.4 Comparative Appraisal Summary 36 6.5 Preferred Route 37 7. CONSULTATION ON THE PROPOSALS 39 7.1 Questions for Consideration by Consultees 39 7.2 Next Steps 39 Figures Figure 1.1 – Location Figure 3.1 – Corridor Figure 3.2 – Route Options and Nodes Figure 5.1 – Key Environmental Constraints Figure 6.1 – Preferred Route Appendices Appendix 1 – Figures Appendix 2 – Summary RAG tables GLOSSARY Term Definition Alignment A centre line of an overhead line OHL, along with location of key angle structures. Amenity The natural environment, cultural heritage, landscape and visual quality. Also includes the impact of SHE Transmission’s works on communities, such as the effects of noise and disturbance from construction activities. Conductor A metallic wire strung from structure to structure, to carry electric current. Consultation The dynamic process of dialogue between individuals or groups, based on a genuine exchange of views and, normally, with the objective of influencing decisions, policies or programmes of action. Corridor A linear area which allows a continuous connection between the defined connection points. The corridor may vary in width along its length; in unconstrained areas it may be many kilometres wide. Environmental Impact Environmental Impact Assessment. A formal process codified by EU directive Assessment (EIA) 2011/92/EU, and subsequently amended by Directive 2014/52/EU. The national regulations are set out in The Electricity Works (Environmental Impact Assessment) (Scotland) Regulations 2017. The EIA process is set out in Regulation 4(1) of the regulations and includes the preparation of an EIA Report by the developer to systematically identify, predict, assess and report on the likely significant environmental impacts of a proposed project or development. Gardens and Designed The Inventory of Gardens and Designed Landscapes lists those gardens or Landscapes (GDLs) designed landscapes which are considered by a panel of experts to be of national importance. Habitat Term most accurately meaning the place in which a species lives, but also used to describe plant communities or agglomerations of plant communities. Kilovolt (kV) One thousand volts. Listed Building Building included on the list of buildings of special architectural or historic interest and afforded statutory protection under the ‘Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997’ and other planning legislation. Classified categories A – C. Micro-siting The process of positioning individual structures to avoid localised environmental or technical constraints. Mitigation Term used to indicate avoidance, remediation or alleviation of adverse impacts. National Scenic Area A national level designation applied to those landscapes considered to be of (NSA) exceptional scenic value. Overhead line (OHL) An electric line installed above ground, usually supported by lattice steel towers or poles. Plantation Woodland Woodland of any age that obviously originated from planting. Riparian Woodland Natural home for plants and animals occurring in a thin strip of land bordering a stream or river. Route A linear area of approximately 1 km width (although this may be narrower/wider in specific locations in response to identified pinch points / constraints), which provides a continuous connection between defined connection points. Route (preferred) A route for the overhead line taken forward to stakeholder consultation following a comparative appraisal of route options. Route (proposed) A route taken forward following stakeholder consultation to the alignment selection stage of the overhead line routeing process. Routeing The work undertaken which leads to the selection of a proposed alignment, capable of being taken forward into the consenting process under Section 37 of the Electricity Act 1989. Scheduled Monument A monument which has been scheduled by the Scottish Ministers as being of national importance under the terms of the ‘Ancient Monuments and Archaeological Areas Act 1979’. 1 Term Definition Semi-natural Woodland Woodland that does not obviously originate from planting. The distribution of species will generally reflect the variations in the site and the soil. Planted trees must account for less than 30% of the canopy composition Site of Special Scientific Areas of national importance. The aim of the SSSI network is to maintain an Interest (SSSI) adequate representation of all natural and semi-natural habitats and native species across Britain. Span The section of overhead line between two structures. Special Area of An area designated under the EC Habitats Directive to ensure that rare, Conservation (SAC) endangered or vulnerable habitats or species of community interest are either maintained at or restored to a favourable conservation status. Special Landscape Area Landscapes designated by Argyll and Bute Council which are considered to be (SLA) of regional/local importance for their scenic qualities. Special Protection Area An area designated under the Wild Birds Directive (Directive 79/409/EEC) to (SPA) protect important bird habitats. Implemented under the Wildlife and Countryside Act 1981. Stakeholders Organisations and individuals who can affect or are affected by SHE Transmission works. Study Area The area within which the corridor, route and alignment study takes place. Terminal Structure A structure (tower or pole) required where the line terminates either at a substation or at the beginning and end of an underground cable section. The National Grid The electricity transmission network in the Great Britain. Volts The international unit of electric potential and electromotive force. Wayleave A voluntary agreement entered into between a landowner upon whose land an overhead line is to be constructed and SHE Transmission Wild Land Area (WLA) Those areas comprising the greatest and most extensive areas of high wildness. It is not a statutory designation, but wild land areas are considered nationally important. 2 PREFACE This Consultation Document has been prepared by WSP UK Ltd. on behalf of Scottish Hydro Electric Transmission plc (SHE Transmission plc) to seek comments from all interested parties on the Preferred Route identified for the proposed Dunoon to Loch Long 132 kV replacement overhead line between the existing Dunoon substation and Tower 15 to the west of Loch Long. The Consultation Document is available online at the project website: www.ssen-transmission.co.uk/projects/dunoon Under normal circumstances, consultation on the project would involve public engagement events held in the local area. However, as a result of the COVID-19 pandemic this has not been possible. To continue engagement on the project SHE Transmission has developed an online consultation tool, to enable the local community to experience the full exhibition from home on a computer, tablet or mobile device. The online exhibition has been designed to look and feel like a real consultation in a community hall, with exhibition boards, maps, interactive videos and the opportunity to share views on the proposals. Visitors will be able to engage directly with the project team, via a live chat function, where they can ask any questions they might have about the project and share their feedback on the current proposals. The virtual consultation events will be taking place via the project website at the following times: • 3rd November 2020; 10am-12.30pm and 5pm-7.50pm Comments on this Consultation Document should be sent to: Helen Batey Community Liaison Manager Scottish and Southern Electricity Networks E: [email protected] M: +44(0)777 453 993 200 Dunkeld Road, Perth, PH1 3AQ All comments are requested by 3rd December 2020. 3 EXECUTIVE SUMMARY Dunoon is currently connected to the wider electricity grid network by a twin-circuit 132 kV double circuit Overhead Line (OHL), supported on steel lattice towers between the existing Whistlefield substation, located north-west of Garelochhead, and the existing Dunoon substation located west of Sandbank, on Holy Loch, a short distance north of Dunoon. The existing OHL west of the Loch Long crossing is supported by an old design suite of metal lattice towers which are coming towards the end of their operational life. The OHL route crosses some very steep and exposed terrain, and has a very high fault rate associated with it during high winds due to the design of tower used in the original build. SHE Transmission have established a requirement to rebuild the OHL between the existing Dunoon substation and Tower 15 to the west of the Loch Long crossing. Due to the requirement to maintain a 132 kV electricity supply to Dunoon during